Process of fractionation



Feb. 6, 1923,

v H. F. PERKINS. PROCESS OF FRACTIONATION- FILED JULY 2,1919.

WITNESSES .20 sired, per unit of oil' treated, than ,is obvapors andcooling fluid so that the former 75 except that the rate of distillationma'yfbe charged from the conduit 2 follow a cir- 80 Patented eh. fi,i923, i f! S-TAS PATENT @FFHCEO HARRY F; PERKINS, OF PITTSBURGH,PENNSYLVANIA, ASSIGNOR 'I'O ROSANOFIE PROCESS COMPANY, OF PITTSBTIRGH,PENNSYLVANIA, A CORPORATION OF DELAWARE.

.. PROCESS OF FRACTIQNATION.

- Ap lication filed July 2,1919. Serial No. 308,145. To allwhomitmayconcem: I sired gasoline, are condensed in any well Be itknownthat I, HARRY F. PERKINS, known or desired type of condenser. residingat Pittsburgh, in the county of Alle- The process may be practiced bythe use,

I gheny and State of Pennsylvania, a citizen of various types ofapparatus, one of which 5 of the United States, have invented or dis. isdiagrammatically illustrated in the 'accovered certain new and usefulImprovecompanying sheet of drawings in which Figments in Processes ofFractionation, of ure 1 is a vertical central sectional view of whichimprovements the following is a the apparatus, and Figure 2 a transversesecspecification. tional view taken on the line 1'III, Fig- 1.0 Myinvention relates to. the separation, ure 1.

by distillation and fractionation, of a com The vapors formed-in a still1, heated in plex mixtureof liquids into two mixtures any suitablemanner, may pass upwardly one of which is lighter'a nd the other heavierthrou h a conduit 2 into the lower end of than the original complexmixture. It G011? a coo ing chamber shown as formed at the 15 sists in anew process which I have dis-fbotjtom of a dephlegmator. The outer wallcovered, and which I havepractically used 36f the cooling chamber issurrounded by on a commercial scale for theseparation. of 'a'jja cket tthrough which a cooling fluid is gasoline. from crude petroleum, with acirculated, the jacket being provided with greater yieldfof gasoline ofthe quality. dean inlet 5 andan outlet 6. To circulate the tainable. byany other commercial process may be cooled uniformly by the latter, fiatknown to me. I v fluid conduits 7 and 8 extend alternately In theprocess which I'fhave discovered, from one side to the other of thejacket at crude oil is distilled-in the-ordinaryflmannerf right anglesto each other. The vapors dis increased very substantially above present'cuitous path, flowing first laterally below the practice. The vaporsresulting from the dis- 'first conduit 8, then upwardly through sidetillation are first cooled uniformly to a conpassages 9 formed betweenthe wall 3 and ,stant temperature which is lower than the the sides ofthe conduit 8, then horizontally 3 initial boiling point of the residue.By such between adjacent faces of conduits 7 and 8, cooling, theparticles ofvapor which contain then upwardly through side passages 10'none of the hydro-carbons desired in the formed between the sides ofconduit 7 and gasoline are condensed and'the condensate the wall 3, andso on until they flow into returned to the still, or otherwisedisposedthe lower end of the dephlegmator. The 35 of. The cooled vapors are.then passed condensate formed in the cooling chamber through adephlegmator, after which they flows in the opposite direction to theflow are uniformly cooled to a constant teinperaofthe vapors, it beingcharacteristic of theture which is substantially the dry-point structurethat the flowing condensatev is suptemperature' of the desired gasoline.'By ported in a thin film adjacent to the vapors 40 this second coolingof the vapors, the heavier which are maintained in thin layersadjahydrocarbons, which, if condensed with cent to the'cooled surfacesof the coolingthe entire body of vapor passed through fluid. conduits. vthe dephlegmator, would 'raiselthe' required As previously stated, thedephlegmator dry-point temperature of the. gasoline, are so constructedthatthe ascending vapors and 45 condensed and caused to flow downwardlydescending distillate are brought into intithrough the dephlegmator.-The dephlegmate contact with each other. For this purmator is soconstructed that the ascending pose the dephlegmator may consist of avervapors' and descending distillate are brought tical shell 11 having aplurality of transverse into intimate contact; in finely subdividedperforate plates 12. In the openings in 50 particles, with the resultthat the ascending these plates there may be secured a pluvaporspartially re-distilled the descending rality of small bore pipes orcapillary tubes distillate. It is in this sense that the term 13 and 14,the tubes 13 extending upwardly dephlegmator is used herein. Finally,the and being for the passage of vapors, and vapors, uncondensed whencooled to substan-v the tubes 14: extending downwardly for the 55tiall'y the dry-point temperature of the depassage, primarily, ofcondensate. Thus the that just described, the temperature of the zones,I have,

condensate flowing downwardly from one to another of the plates 12 willbe divided .duit 16 to a suitable condenser 17 in which they arecondensed to liquid gasoline.

As a specific example of the temperatures whichmay be-maintained in thecooling in the distillation of Pennsyl- Vania crude for the recovery ofgasoline having a dry point temperature of 220 C., maintained the lowertemperature zone at 230 -C.,- which is below the initial boiling pointof the residue, and the upper cooling zone at 220 C. Atsuchtemp'eratures, I'have, on a commercial scale, recovered 11 per centof the crude as gasoline having a dry point temperature of 220 C., andotherwise meeting the physical requirements of gasoline as to averageboiling point, initial boiling point and gravity. In a similar manner. Ihave from the same crude oil, obtained a yieldot 33 percent of gasolinehaving a dry point temperature of 183 C.

If it is desired to obtain a out other than top cooling zone should bemaintained at the dry point temperature the required cut. After thegasoline has been removed from the crude oil, the kerosene may berecovered in similar manner by maintaining the temperature of the topcooling zone at about the required dry point temperature of the keroseneand thetemperature'of the lower cooling zone at a temperature below theinitial boiling point ot the residue but above the temperature of thetop cooling zone. The two cuts, gasoline and kerosene, may be removedseparately by one apparatus or, in part, simultaneously by using twosets of apparatus arranged successively. The distillation may beeffected either in batch or continuously and at a rate substantiallyabove that of present practice. In the case of the residue itsadaptability to the separation of gasoline from petroleum, it manifestlyis applicable to the recovery of gasoline or other cuts from otherhydrocarbon mixtures such as coal or shale oil, and by extension theprocess is applicable to the separation of any complex mixture of liquidinto two mixtures, a heavier and a lighter, the lighter having arequired dry point temperature.

I claim as my invention:

1. The process of separating a mixture of liquid substances of differentvolatility into a lightersubstance and a heavier residue, which consistsin distilling the mixture, cooling .the vapors of distillation to atemperature lower than the initial boilin point to be obtained, passingthe cooled uncondensed vapors through a dephlegmator in contact withcondensate and cooling the vapors passed through the dephlegmator tosubstantially the dry point of the lighter substance to be obtained, andthen condensing the uncondensed vapors.

2. The process of obtaining gasoline from a hydrocarbon mixturecontaining it which consists in distilling the mixture, coolingthevapors of distillation to a temperature lower than the initial boilingpoint of the residue to be obtained, passing the cooled nncondensedvapors through a dephlegmator in contact with condensate and cooling thevapors passed through the dephlegmator to substantially the dry point ofthe gasoline to be obtained, and then condensing the uncondensed vapors.

- In testimony whereof I have hereunto set my hand.

HARRY F." PERKINS.

Vitnesses PAUL N. Cnrrorrnow, FRANCIS J. TOMASSON.

